This study describes the cues and factors that influence the decision making process used by nurses when identifying and interrupting a potential adverse event in the acute care setting. The adverse event of interest was preventable in-hospital cardiopulmonary arrest. Research Questions: (1) What cues do registered nurses use to identify that a patient is at risk for an adverse event (cardiopulmonary arrest)? (2) What factors influence the registered nurses decision to interrupt an adverse event (cardiopulmonary arrest)? The study was supported by assumptions from the nursing role effectiveness model which highlights decision making as an independent role of the nurse. This was a qualitative study using the cognitive task analysis method of the Critical Decision Method. The Critical Decision Method (CDM), derived from the recognition primed decision model (RPD) and naturalistic decision making paradigm was used to elicit nurses decision making in the complex, high stakes, real time, and real world pre-arrest period. The following cues were used by nurses to identify risk for an adverse event: physiological data including subtle changes in mental status and trends in vital signs, and knowledge about the patient in terms of history, severity of illness, information from report and knowing the patient as an individual. Factors which affected interruption of an event included organizational resources such as independent use of monitoring equipment, personnel in terms of experience, teamwork and flexibility and knowledge including knowledge about the patient, knowledge from past experiences, and knowledge about the organization. The cues and factors revealed here are also influenced by macrocognitive perspectives inherent in the study setting. The nurses in this study operated from a perspective of maintaining patient safety while balancing organization expectations. Examination of these decision situations demonstrated the complexity of clinical practice and the many factors that affect nurse\u27s ability to identify and interrupt adverse events. This study demonstrated that the patient\u27s experience of illness, severity of illness and trends over time are useful in identifying risk of clinical deterioration. Teamwork and flexibility was evident among the unit nursing staff and across disciplines. When team members knew and trusted each other, they were better positioned to share decision making and adapt to rapidly changing conditions. Lastly this study demonstrated the importance of knowledge management as an organization resource
